This invention is in the field of video cameras and in particular camera bodies that protect the camera components from vibration and exposure to the environment.
Video cameras are used in all sorts of different industries to visually monitor various activities and locations. Often these cameras are subject to hostile ambient conditions, and exposed to vibration, dust, corrosive fumes, moisture, and the like that can lead to premature malfunctioning of the camera. As well cold can be detrimental to the operation of the camera and require added heating elements.
Typically such cameras are made up of various components mounted in a camera body. For example the popular charge coupled device (CCD) camera components are mounted on one or more printed circuit boards that are operatively connected to a lens. Such cameras may be purchased with the circuit boards mounted in a camera body with the lens extending through an opening in the body, and output and power connecting wires leading from the circuit boards out of the camera body. Alternatively the circuit boards and lens can be purchased alone and these can be mounted in such manner as the customer desires.
Conventionally protection from ambient conditions is provided by sealing the camera body to prevent contact of the camera components with the ambient air. Resilient mounts are commonly provided to reduce vibration, and heaters are provided to ensure proper operation in cold conditions.
U.S. Pat. No. 5,089,895 to Fraker et al. discloses a camera body encapsulated in a plastic material. The camera body is placed in a mold, and a plastic material such as urethane, silicone, polystyrene or the like is injected into the mold. When the plastic material hardens, the mold is removed. The camera body is thus encased in the plastic material, which is exposed to ambient conditions. The process requires significant time for preparation of a mold, properly placing the camera in the mold, injecting and hardening the plastic material, and then removing the mold. As well, the camera components are still subject to vibration inside the camera body.
It is the object of the present invention to provide a video camera apparatus wherein components of the camera are protected from exposure to ambient conditions.
It is a further object of the invention to provide such an apparatus wherein components of the camera are encapsulated in a solid filler material such that portions of the components are inhibited from moving with respect to each other.
It is a further object of the invention to provide a method of making a video camera apparatus wherein components of the camera are encapsulated in a solid filler material.
The invention provides, in one aspect, a video camera apparatus comprising a camera body and a lens attached to the camera body and operative to view an exterior of the camera body. A plurality of camera components is substantially enclosed in an interior of the camera body and operatively connected to the lens. Connectors lead from the camera components to the exterior of the camera body and are operative to transmit images viewed by the lens to a remote viewer. A solid filler material substantially covers the camera components and secures the camera components in a fixed location with respect to the camera body. The filler material has sufficient insulating properties to prevent generation of a current through the filler material by voltages normally encountered on exposed portions of the camera components. The filler material is injected into the camera body in a fluid state, and then hardens to a solid state.
The invention provides, in a second aspect, a method of assembling a video camera apparatus comprising substantially enclosing a plurality of camera components in an interior of a camera body and attaching a lens to the camera body and orienting the lens such that the lens is operative to view an exterior of the camera body. The lens is operatively connected to the camera components. Connectors are provided leading from the camera components to the exterior of the camera body, the connectors operative to transmit images viewed by the lens to a remote viewer. A fluid filler material is injected into the camera body so as to substantially cover the components and so as to fill at least a portion of a space between each camera component and an interior wall of the camera body to secure the camera components in a fixed location with respect to the camera body when the filler material hardens. The fluid filler material is allowed to harden to a solid state. The filler material has sufficient insulating properties to prevent generation of a current through the filler material by voltages normally encountered on exposed portions of the camera components.
The camera of the invention thus has a camera body that contains the required components for the operation of the camera connected to a lens. When the camera will be working in a harsh environment, where the ambient air carries dust, moisture, corrosive gases, and so forth, it is necessary to prevent the ambient air from contacting the camera components. Conventionally the camera body is sealed around the lens, connectors, and body cover to prevent the entry of ambient air, liquids, gases and so forth into the cavity containing the camera components. In the camera of the invention, the camera components are covered with the solid filler material such that these ambient conditions are prevented from contacting the camera components. Further the filler material secures the camera components in the camera body by filling at least a portion of the space between the components and the inside wall of the camera body. Further the filler material insulates the camera components and can allow operation in colder conditions without adding a heater. Conveniently the cavity is simply substantially filled with a solid filler material, such as silicone, which occupies substantially all the space inside the camera body that is not occupied by camera components.
The camera components may have operating voltages on exposed surfaces. The filler material must have insulating properties that will not allow a current or xe2x80x9cshortxe2x80x9d to be generated from one portion of the components to another through the filler material.
Often cameras are exposed to vibration that can cause component connections to break as one portion of the components moves with respect to the other portions. In the camera of the invention, the solid filler material inhibits such relative movement.
The filler material is one of a number of known materials that can be injected into the camera body in a fluid state, and then hardens as a result of exposure to air, or heat or the like. Silicone compounds can be used which will harden into a resilient block. These are inexpensive and easily injected by a caulking gun for example. Alternatively, epoxy compounds or the like can be used which harden into a rigid block.